Acquiring the parts for the Duckiebot C0

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The trip begins with acquiring the parts. Here, we provide a link to all bits and pieces that are needed to build a Duckiebot, along with their price tag.

In general, keep in mind that:

  • The links might expire, or the prices might vary.
  • Shipping times and fees vary, and are not included in the prices shown below.
  • Substitutions are OK for the mechanical components, and not OK for all the electronics, unless you are OK in writing some software.
  • Buying the parts for more than one Duckiebot makes each one cheaper than buying only one.

Resources necessaries:

  • Cost: USD 193.50 + Shipping Fees (configuration D17-0)
  • Time: 15 days (average shipping for cheapest choice of components)

Results:

  • A kit of parts ready to be assembled.

Add a different “Tools” section in the table (e.g., solderer), or add in the resoruces beginning snippet; Differentiate pricing for bulk vs detail purchase (?)

Bill of materials

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Bill of materials
Chassis USD 20
Camera with 160-FOV Fisheye Lens USD 22
Camera Mount USD 8.50
300mm Camera Cable USD 2
Raspberry Pi 3 - Model B USD 35
Heat Sinks USD 5
Power supply USD 7.50
16 GB Class 10 MicroSD Card USD 20
Mirco SD card reader USD 6
Tiny 32GB USB Flash Drive USD 12.50
Stepper Motor HAT USD 22.50
Stacking Headers 2 for D17-1, 1 otherwise USD 2.50/piece
Battery USD 20
16 Nylon Standoffs (M2.5 12mm F 6mm M USD 0.05/piece
4 Nylon Hex Nuts (M2.5) USD 0.02/piece
4 Nylon Screws (M2.5x10) USD 0.05/piece
2 Zip Ties (300x5mm) USD 8.99
Wifi Augmenter (D17-0+w) USD 20
Joypad (D17-0+j) USD 10.50
20 Female-Female Jumper Wires (300mm) (D17-1) USD 8
Male-Male Jumper Wire (150mm) (D17-1) USD 1.95
LEDs (D17-1) USD 10
LED HAT (D17-1) USD 28.20 for 3 pieces
PWM/Servo HAT (D17-1) USD 17.50
40 pin female header (D17-1) USD 1.50
Bumpers (D17-1) TBD (custom made)
5 4 pin female header (D17-1) USD 0.60/piece
2 16 pin male header (D17-1) USD 0.61/piece
12 pin male header (D17-1) USD 0.48/piece
3 pin male header (D17-1) USD 0.10/piece
2 pin female shunt jumper (D17-1) USD 2/piece
5 200 Ohm resistors (D17-1) USD 0.10/piece
10 130 Ohm resistors (D17-1) USD 0.10/piece
Total for D17-0 configuration USD 191.50
Total for D17-0+w configuration USD 211.50
Total for D17-0+j configuration USD 222
Total for D17-1 configuration USD 281+Bumpers

Chassis

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We selected the Magician Chassis as the basic chassis for the robot (Figure 2).

We chose it because it has a double-decker configuration, and so we can put the battery in the lower part.

The chassis pack includes the motors and wheels as well as the structural part.

The price for this in the US is about USD 15-30.

The Magician Chassis

Raspberry Pi 3 - Model B (RPI-3)

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The RPI-3 is the central computer of the Duckiebot. Duckiebot version D17 uses Model B (Figure 3) (A1.2GHz 64-bit quad-core ARMv8 CPU, 1GB RAM), a small but powerful computer.

The Raspberry Pi 3 Model B

The price for this in the US is about USD 35.

Power Supply

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We want a hard-wired power source (5VDC, 2.4A, Micro USB) to supply the RPI-3 (Figure 4).

The Power Supply

The price for this in the US is about USD 5-10.

Heat Sinks

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The RPI-3 will heat up significantly during use. It is warmly recommended to add heat sinks, as in Figure 5. Since we will be stacking HATs on top of the RPI-3 with 15 mm standoffs, the maximum height of the heat sinks should be well below 15 mm. The chip dimensions are 15x15 mm and 10x10 mm.

The Heat Sinks

Class 10 MicroSD Card

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The MicroSD card (Figure 6) is the hard disk of the RPI-3. 16 Gigabytes of capacity are sufficient for the system image.

The MicroSD card

Mirco SD card reader

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A MicroSD card reader (Figure 7) is useful to copy the system image to a Duckiebot from a computer to the RPI-3 microSD card, when the computer does not have a native SD card slot.

The Mirco SD card reader

Tiny 32GB USB Flash Drive

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This “external” hard drive (Figure 8) is very convenient to store logs during experiments and later port them to a workstation for analysis. It provides storage capacity and faster data transfer than the MicroSD card.

The Tiny 32GB USB Flash Drive

Camera

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The Camera is the main sensor of the Duckiebot. Version D17 equips a 5 Mega Pixels 1080p camera with wide field of view ($160^\circ$) fisheye lens (Figure 9).

The Camera with Fisheye Lens

Camera Mount

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The camera mount (Figure 10) serves to keep the camera looking forward at the right angle to the road (looking slightly down). The front cover is not essential.

The Camera Mount

300mm Camera Cable

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A longer (300 mm) camera cable Figure 11 make assembling the Duckiebot easier, allowing for more freedom in the relative positioning of camera and computational stack.

A 300 mm camera cable for the RPI-3

Wifi Augmenter

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The Edimax AC1200 EW-7822ULC wifi adpater (Figure 12) boosts the connectivity of the Duckiebot, especially useful in busy Duckietowns (e.g., classroom).

The Edimax AC1200 EW-7822ULC wifi adapter

Joypad

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The joypad is used to manually remote control the Duckiebot. Any 2.4 GHz wireless controller (with a tiny USB dongle) will do.

The model link in the table (Figure 13) does not include batteries (2 AA 1.5V)!

A Wireless Joypad

DC Stepper Motor HAT

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We use the DC Stepper motor HAT (Figure 13) to control the DC motors that drive the wheels. This item will require soldering to be functional.

The Stepper Motor HAT

Stacking Headers

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We use long 20x2 stacking headers (Figure 15) to connect the RPI-3 with the other HATs, creating a stack. This item will require soldering to be functional.

In configuration D17-1, we need 2 stacking headers.

In all configurations, we use only 1 stacking header.

The Stacking Headers

Battery

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The battery (Figure 16) provides power to the Duckiebot.

We choose this battery because it has a good combination of size (to fit in the lower deck of the Magician Chassis), high output amperage (2.4A and 2.1A at 5V DC) over two USB outputs, a good capacity (10400 mAh) at an affordable price (USD 20).

The Battery

Standoffs, Nuts and Screws

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We use non electrically conductive standoffs (M2.5 12mm F 6mm M), nuts (M2.5), and screws (M2.5x10mm) to hold the RPI-3 to the chassis and the HATs stacked on top of the RPI-3.

In configuration D17-0 and D17-0+w or D17-0+j, the Duckiebot requires 8 standoffs, 4 nuts and 4 screws.

In configuration D17-1, the Duckiebot requires 16 standoffs, 4 nuts and 4 screws.

Standoffs, Nuts and Screws

Zip Tie

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Two 300x5mm zip ties are going to be useful to keep the battery at the lower deck from moving around.

The zip ties

LEDs

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In configuration D17-1, the Duckiebot is equipped with 5 RGB LEDs. LEDs can be used to signal to other Duckiebots, or just make cool patterns!

The pack of LEDs linked in the table above holds 10 LEDs, enough for two Duckiebots.

The RGB LEDs

LED HAT

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In configuration D17-1, the LED HAT (Figure 20) provides an interface for our RGB LEDs and the computational stack. This board is a daughterboard for the Adafruit 16-Channel PWM/Servo HAT, and enables connection with additional gadgets such as ADS1015 12 Bit 4 Channel ADC, Monochrome 128x32 I2C OLED graphic display, and Adafruit 9-DOF IMU Breakout - L3GD20H+LSM303. This item will require soldering to be functional.

This board is custom degined and can only be ordered in minimum runs of 3 pieces. The price scales down quickly with quantity, and lead times may be significant, so it is better to buy these boards in bulk.

The LED HAT

PWM/Servo HAT

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In configuration D17-1, the PWM/Servo HAT HAT (Figure 21) mates to the LED HAT and provides the signals to control the LEDs, without taking computational resources away from the Rasperry Pi itself. This item will require soldering to be functional.

The PWM-Servo HAT

Male-Male Jumper Wires

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In configuration D17-1, the Duckiebot requires one male-male jumper wire (Figure 22) to power the DC Stepper Motor HAT from the PWM/Servo HAT.

Premier Male-Male Jumper Wires

Female-Female Jumper Wires

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In configuration D17-1, 20 Female-Female Jumper Wires (Figure 23) are necessary to connect 5 LEDs to the LED HAT.

Premier Female-Female Jumper Wires

Bumpers

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These bumpers are designed to keep the LEDs in place and are therefore used only in configuration D17-1. They are custom designed parts, so they must be produced and cannot be bought. We used laser cutting facilities. Our design files are available [here].

add links to .sldprt files once confirmed final version

The Bumpers

Passive Electric Components

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5 4 pin female header

2 16 pin male header

1 12 pin male header

1 3 pin male header

1 2 pin female shunt jumper

5 200 Ohm resistors

10 130 Ohm resistors

These items will require soldering to be functional.

The Headers
The Resistors

Clean up

Because of mathjax bug
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